Bioavailable Ferric Iron (BAFelll) Assay
Cost and performance rept.
NAVAL FACILITIES ENGINEERING COMMAND PORT HUENEME CA ENGINEERING SERVICE CENTER
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CDM invented and developed a bioavailable ferric iron BAFeIII assay with funding from the U.S. Air Force USAF. This is a standardized bioassay that directly measures the concentration of BAFeIII in soil or sediment. A BAFeIII test kit based on the assay is manufactured by New Horizons Diagnostics Corporation NHD of Columbia, Maryland. BAFeIII is defined as ferric iron FeIII that is capable of being reduced by microorganisms that oxidize another chemical species and derive energy from the electron transfer. BAFeIII is an important terminal electron acceptor with significant assimilative capacity in many natural environments. Dissolved ferrous iron FeII in groundwater is typically measured to assess FeIII reduction and calculate assimilative capacity, but this measurement underestimates this terminal electron accepting process TEAP because most FeII remains bound to the soil. Dissolved FeII also gives no indication of the amount of FeIII present in aquifer soil that is bioavailable. BAFeIII in the soil must be measured in order to quantify the true assimilative capacity of an aquifer. Iron-reducing bacteria FeRB use and are dependent on BAFeIII. FeRB are known to oxidize or mineralize various organic compounds, such as benzene, toluene, vinyl chloride VC, and methyl tertiary butyl ether MTBE. Continued activity over a period of years is dependent on the presence of sufficient BAFeIII. BAFeIII can also affect reductive dechlorination in monitored natural attenuation MNA and enhanced anaerobic biodegradation EAB applications. BAFeIII can result in trichloroethene TCE being reductively dechlorinated to cis-Dichloroethene cDCE only, and further reductive dechlorination can be inhibited AFCEE, 2004. Thus, knowledge of the BAFeIII concentration can indicate the potential for incomplete reductive dechlorination of TCE. It can also be used for planning EAB remedies.
- Inorganic Chemistry
- Water Pollution and Control